Getting ready to build a chicken tractor for meat birds coming in a couple weeks. gonna have a 4ft X4ft coop or enclosure connected to a 4ft X10ft run covered with welded wire.. What do you do for the floor of the run. Leave it open, so the chickens can get to the ground or use welded wire. . If I leave it open, I ll do a 1 ft apron around the base. Will that stop predators from digging underneath.